10.23.2011

[N.B.: For whatever reason, the footnotes to this paper don't show up here.]

In §§6.0-1 of his book The Myth of Morality, Richard Joyce tells a story about the evolutionary origins of our moral beliefs. According to Joyce, humans evolved first a disposition toward thinking of helping kin as morally required, and second a disposition toward thinking of reciprocal helping among non-kin individuals as morally required. Thus, our moral beliefs - or at least our disposition to view certain actions as morally required - are the result of natural selection.

In §6.4, Joyce argues that, if this story about our moral beliefs is true, then our moral beliefs are unjustified, because we have evolved the disposition to have such beliefs irrespective of their truth:

Suppose that the actual world contains real categorical [i.e., moral] requirements - the kind that would be necessary to render moral discourse true. In such a world humans will be disposed to make moral judgments ... for natural selection will make it so. Now imagine instead that the actual world contained no such requirements at all - nothing to make moral discourse true. In such a world humans will still be disposed to make these judgments ... just as they did in the first world, for natural selection will make it so.#

Put differently, because the disposition to have moral beliefs (i.e., make moral judgments) would be evolutionarily advantageous to us whether or not there were moral truths, we would evolve such a disposition - and, consequently, come to have moral beliefs - whether or not there were moral truths (and, a fortiori, whether or not our particular moral beliefs were true). But if we have come to have moral beliefs irrespective of the truth of those beliefs - if, as Joyce puts it, “the process that generates moral judgments exhibits an independence relation between judgment and truth” - then our moral beliefs are unjustified.# (For Joyce, a belief is justified only if it is formed by a reliable process such that one’s coming to have that belief depends in some way on the belief’s truth.)

In this essay, I will assume that Joyce’s story in §§6.0-1 is correct and focus exclusively on a criticism of Joyce’s argument in §6.4 made by Robert Nozick.# I will argue that Nozick’s criticism fails to undermine Joyce’s argument and that the argument is therefore sound if the story in §§6.0-1 is correct.

In response to the assertion that we have come to have moral beliefs irrespective of the truth of those beliefs, Nozick writes,

[E]thical behavior will serve inclusive fitness through serving or not harming others, through helping one's children and relatives, through acts that aid them in escaping predators, and so forth; that this behavior is helpful and not harmful is not unconnected to why (on most theorist's views) it is ethical. The ethical behavior will increase inclusive fitness through the very aspects that make it ethical, not as a side effect through features that only accidentally are connected with ethicality.#

According to Nozick, the aspects of our behavior which make it moral are the very same aspects which make it evolutionarily advantageous. As a result, Nozick argues that Joyce’s argument in §6.4 is unsound, because it is not the case that we have come to have moral beliefs irrespective of their truth.

Consider, after all, some non-moral property A of some behavior x.# Suppose that the following is true: Because x is A (because x has the property of A-ness), x is both morally required and evolutionarily advantageous.# If x were not A, then x would be neither morally required nor evolutionarily advantageous. But if x is not evolutionarily advantageous when it is not morally required - that is, precisely when it is not A - then it is not the case that we come to believe that x is morally required (or even come to be disposed to believe that x is morally required) irrespective of the truth of that belief. For if it were not true that x is morally required, then it also would not be true that x is evolutionarily advantageous, and thus not true that we would come to believe that x is morally required. Therefore, since it is not the case that we come to believe that x is morally required irrespective of the truth of that belief, Joyce’s argument in §6.4 is unsound.

In this reply to Joyce’s argument, Nozick takes into consideration two possible worlds: one (call it “Nozick-1”) in which x is A, morally required, and evolutionarily advantageous, and one (“Nozick-2”) in which x is not A, not morally required, and not evolutionarily advantageous. Clearly, it is not the case that we come to believe that x is morally required in both Nozick-1 and Nozick-2 (i.e., whether or not x is A), because x is not evolutionarily advantageous in Nozick-2 (because x is not A in Nozick-2). But this fact - the crux of Nozick’s reply - is irrelevant to Joyce’s argument, because Nozick-2 is physically different from the actual world,# and consequently not one of the worlds which Joyce takes into consideration in his argument in §6.4. After all, Joyce can agree with Nozick that we would not come to believe that x is morally required in Nozick-2 and still argue that we would come to believe that x is morally required in both of two possible worlds physically identical to the actual world which differ only in that certain behaviors (including x) are morally required in one and no behaviors (including x) are morally required in the other. But if we come to believe that x is morally required in both of those possible worlds, then we come to believe that x is morally required whether or not x is morally required, and Joyce’s argument in §6.4 stands.

This response to Nozick can be formulated more explicitly. If A does not necessarily make x morally required - if, in other words, it is possible that x is A and evolutionarily advantageous but not morally required - then we can speak of two worlds: one in which x is A, evolutionarily advantageous, and morally required (Nozick-1) and one in which x is A and evolutionarily advantageous but not morally required (“Joyce-3”).# It is Nozick-1 and Joyce-3, not Nozick-1 and Nozick-2, that correspond to the two possible worlds Joyce discusses in the excerpt from §6.4 quoted above: one in which the actual world (i.e., the world in which x is A and evolutionarily advantageous) is such that certain behaviors (including x) are morally required - that is, Nozick-1 - and one in which the actual world is such that no behaviors (including x) are morally required - that is, Joyce-3.# To undermine Joyce’s argument, Nozick must demonstrate that it is not the case that we come to believe that x is morally required in both Nozick-1 and Joyce-3 (i.e., whether or not x is morally required). But Nozick has not demonstrated that claim; he has demonstrated only that it is not the case that we come to believe that x is morally required in both Nozick-1 and Nozick-2. As a result, Joyce’s argument in §6.4 stands.

Importantly, this response to Nozick is successful only if A does not necessarily make x morally required. If A does necessarily make x morally required - if, in other words, it is impossible that x is A but not morally required - then Joyce-3 is not a possible world, and Joyce’s argument in §6.4 fails.# Joyce’s argument against such a claim can be sketched briefly here: Suppose that x is some sexual act and A is the property of being an episode of incest. Then, the claim in question (“E”) is “If x is an episode of incest, then, necessarily, x is morally forbidden.”# If E is true, then there is no possible world in which x is A but not morally forbidden, and the response to Nozick fails; if E is false, then the response to Nozick succeeds and Joyce’s argument in §6.4 stands.

One could defend E by contending that it is simply a brute fact, but Joyce finds such a contention ad hoc and unattractive,# as do I. Consider, in addition, the following famous occurrence of incest: Oedipus married his mother Jocasta and had sex with her without knowing that she was his mother. Is he morally responsible for these episodes of incest (assuming that they were morally forbidden) if he did not recognize them as such? If not, were his sexual acts with his mother morally forbidden even if he did not know that they were episodes of incest? It is plausible - or at least possible - that they were not morally forbidden under the circumstances. But if that claim is true, then E is false.#

Alternatively, one could attempt to establish E by employing some intermediate step: “If x is an episode of incest, then x is psychologically traumatic to someone; and if x is psychologically traumatic to someone, then, necessarily, x is morally forbidden.” But this first conditional appears to be false; as Joyce argues, “We can easily imagine circumstances in which ... incest does not lead to [psychological] trauma” (e.g., circumstances in which the parties committing incest do not realize that they are committing incest, as was the case for Oedipus and Jocasta).# Indeed, any such conditional appears to be false; counterexamples such as the Oedipus counterexample can be offered for all of them. As a result, there appears to be no reason to accept E, and consequently no reason to reject the initial response to Nozick.

Nozick’s reply to Joyce’s evolutionary argument fails once we recognize that Joyce’s argument takes Nozick-1 and Joyce-3 into consideration rather than Nozick-1 and Nozick-2. Furthermore, the claim that A necessarily makes x morally required (or forbidden) - which, if true, could salvage Nozick’s reply - is not very plausible. Thus, Joyce’s argument in §6.4 is sound if Joyce’s story in §§6.0-1 is correct.